Habitat disturbance, be that logging, agriculture, or roads and infrastructure, can be hugely damaging to biodiversity. But even after the visible wounds have healed, the genetic scars of past disturbance remain in the genome, according to results from a two-decade-long study of shrubs in Spain.
The effects of habitat disturbance on plants can be seen in the genomes of the next generation, a new study reports for the first time. The team compared the genetic and epigenetic profiles of shrubs (Lavandula latifolia) that had been experimentally disturbed 20 years previously, with those left undisturbed for more than 50 years.
There are more than 10,000 species of living, breathing dinosaurs on Earth today. It’s just that we call them birds. And while a chicken might seem like a measly ancestor for the enormous T-rex, modern birds can teach us a lot about dinosaur evolution. A huge genome sequencing project, which recently culminated in the publication of nearly 50 genome sequences and the most accurate tree of bird evolution to date, has further blurred the line between bird and dinosaur. Spurring a plethora of studies into the origins of our modern feathered, singing friends, the December 2014 edition of Science taught us that the transition from dinosaurs to birds was gradual and began long before the Dinosaurs were gone. It taught us that it involved multiple independent origins of bird song, a characteristic that now dominates around 10% of the genome. And it taught us that the evolution of flight was facilitated by new genes and new gene regulation, but also by the loss of genes.
Making a Chicken from a T-Rex
Last October, the Therapod Working Group constructed a new phylogeny (family tree) for Dinosaurs, based on morphological characteristics measured in fossil remains of over 150 different species. The new tree revealed fascinating insights into the nature and pace of avian evolution.
Cats are one of the most common domesticated animal on Earth, with an estimated 400 million worldwide. And yet they lack many characteristics that tended to make animals good for domestication. They are solitary hunters, making them relatively poor at responding to and valuing social hierarchies. So how exactly did early humans domesticate our feline friends? Recent research suggests stroking and treats may have been key to winning them over.
Symbiotic relationships, where two organisms ‘live together’ and rely upon each other to survive, are surprisingly common in the animal kingdom. The more we look, the more we find. What is less common, or at least less well documented, is the occurrence of speciation events within these partnerships. A recent study has revealed the first documented case of the speciation of a bacterial symbiont, inside the cells of a cicada. Even more interestingly, scientists believe it may have been little more than an evolutionary screw-up!
Symbiotic relationships can be quite casual, or extremely intimate, and are literally all around you. And inside you. The mitochondria inside your cells are symbiotic bacteria that joined our cells billions of years ago. Mitochondria show a pattern that is common in such intimate symbiotic relationships – over millions of years, partners in the relationship each have a reduced genome, with a complementary set of genes. This in turn makes them even more dependent upon each other. Mitochondria have only about 37 genes, compared to 1000 in a free-living bacteria. They simply don’t need many of their genes anymore because their host cells carry them. This is known as relaxed selection – because both members of the partnership carry the genes, a mutation in a gene in one partner will probably have no effect. The other member still has a functioning version of that gene, so the organism as a whole shows no negative symptoms, and natural selection is blind to the mutation. Only when both copies of a particular gene are degraded will natural selection step in, meaning that over time random chance will degrade complementary sections of each genome.
Each second 26,000 cups of coffee are consumed globally. That’s over 93 million cups an hour, or an astonishing 2 billion cups a day! Why is coffee the most popular beverage on Earth? Well it might have something to do with all that lovely caffeine it contains. We are a species thoroughly addicted to caffeine; the most popular psychoactive substance in the world. Recent research into the genomics of the coffee plant is shedding some light on the evolutionary processes behind the world’s most popular drug, and revealing some of the reasons it is popular not just with humans, but with insects, too.
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